1. Field of the Invention
The present Invention relates to a device for transferring flat, flexible, non-self-supporting printed products from a line conveyor to a receiving device like a conveyor or a bundler. The present Invention is especially useful for handling newspapers.
2. Art Relating to the Invention
In the graphic arts industry, flat, flexible, non-self-supporting printed products, such as newspapers and magazines, are moved by line conveyors. At some point along their path, the product has to be transferred from the line conveyor to another conveyor, a bundler, or other type of receiving device for further processing a stacker. The bundler/stacker prepares stacks of product for shipment, future binding, handling, or processing.
Typically, a line conveyor, as employed in the graphic arts industry, is a horizontally oriented endless chain which is equipped with a plurality of vertically oriented grippers. The grippers clamp the top edge of the product and transports the product to the receiving device. When the product arrives at the receiving device, the gripper opens its jaws to allow the product to fall from the gripper onto another conveyor, a platform or stack of other products, depending on the type of receiving device to which the product is transferred to at the transfer point.
One of the transfer devices used with bundlers/stackers as taught in U.S. Pat. No. 5,218,813 uses a circular conveyor which transfers the product from the line conveyor to the bundler/stacker. The circular conveyor employs grippers which grip the bottom edge of the product and rotate the product around to the bundler/stacker.
There is a point in time, just prior to release of the product from the line conveyor gripper, when the product is held by both the line conveyor gripper and the circular conveyor gripper. At this point in time, the product is subject to forces in opposite directions which can lead to problems in transferring the product from one conveyor to the other.
Additionally, there are times when the product is intended for a subsequent bundler/stacker and the line conveyor gripper does not release the product. In this situation, the circular conveyor grippers pulls the product out of the jaws of the line conveyor grippers. There is a need to avoid the fight between the line conveyor grippers and the circular conveyor grippers.